Antimicrobial composite and method of manufacture and use

Abstract

An antimicrobial composite is provided, comprising a catalyst capable of promoting oxidation of organic molecules incorporated in a carrier, for example a hydrophilic or water-based material, the catalyst configured such that it will not discolor surrounding material under the influence of oxidative conditions

1 . A method of making a hydrogel having antimicrobial properties, the method comprising: 
 mixing a hydrogel-forming polymer with water; and    applying an energy source to crosslink the mixture of hydrogel-forming polymer and water to form the hydrogel;    wherein the hydrogel further includes a silver antimicrobial agent that does not discolor.    
     
     
         2 . The method of  claim 1 , wherein the hydrogel-forming polymer is a hydrophilic polymer.  
     
     
         3 . The method of  claim 2 , wherein the hydrophilic polymer is selected from starch, cellulose, cellulose derivatives, polyvinyl alcohol, polyalkylene oxide, polyethylene oxide, polypropylene glycol, poly(1,3-dioxolane), copolymers of polyethylene oxide, copolymers of poly(1,3-dioxolane), polyvinyl pyrrolidone, polyethylene glycol, polyacrylic acid, polymethylene oxide, or a combination thereof.  
     
     
         4 . The method of  claim 1 , wherein the hydrogel-forming polymer is added to the water in a weight ratio ranging from about 1 part hydrogel-forming polymer to about 33 parts water to about 1 part hydrogel-forming polymer to about 3 parts water.  
     
     
         5 . The method of  claim 1 , wherein the silver antimicrobial agent comprises nanoparticulate silver.  
     
     
         6 . The method of  claim 5 , wherein the silver antimicrobial agent further comprises silver flakes having an average longest dimension of about 0.1 micrometers to about 20 micrometers.  
     
     
         7 . The method of  claim 1 , wherein the silver antimicrobial agent is added to the hydrogel in an amount of from about 0.1 to about 10% by weight.  
     
     
         8 . The method of  claim 7 , wherein the silver antimicrobial agent is added to the hydrogel in an amount of from about 0.1 to about 3% by weight.  
     
     
         9 . The method of  claim 1 , wherein the silver antimicrobial agent is mixed with the hydrogel-forming polymer and the water prior to application of the energy source.  
     
     
         10 . The method of  claim 1 , wherein the mixture of the hydrogel-forming polymer and the water is applied to a substrate prior to application of the energy source.  
     
     
         11 . The method of  claim 10 , wherein the substrate is selected from a top sheet, a bottom sheet, a scrim, or a combination thereof.  
     
     
         12 . The method of  claim 11 , wherein the substrate comprises a scrim selected from a mesh, a foam, a film, a woven material, a non-woven material, or a combination thereof.  
     
     
         13 . The method of  claim 12 , wherein the scrim comprises a high-density expanded polyethylene web.  
     
     
         14 . The method of  claim 1 , further comprising an additive selected from an anti-fungal additive, an antimicrobial additive, a salt, a preservative, a pH adjuster, a crosslinking inhibitor, or a combination thereof.  
     
     
         15 . The method of  claim 1 , wherein the energy source is selected from an electron beam, gamma radiation, or a combination thereof.  
     
     
         16 . The method of  claim 15 , wherein the energy source comprises a linear accelerator electron beam.  
     
     
         17 . A hydrogel having antimicrobial properties made according to the process of  claim 1 .  
     
     
         18 . A personal care product having antimicrobial properties comprising the hydrogel of  claim 17 .  
     
     
         19 . The personal care product of  claim 18 , wherein the personal care product is selected from a bandage, a cosmetic, a topical skin treatment, a wound dressing, a diaper, or a feminine care article.  
     
     
         20 . The method of  claim 1 , wherein the hydrogel is substantially free of any additive for enhancing crosslinking.  
     
     
         21 . A composite, comprising a carrier and particulate silver, wherein the composite does not discolor when exposed to aqueous conditions for at least about 24 hours.  
     
     
         22 . The composite of  claim 21 , wherein the composite is antimicrobial.  
     
     
         23 . The composite of  claim 21 , wherein the composite does not discolor surrounding material when exposed to oxidative conditions.  
     
     
         24 . The composite of  claim 21 , wherein discoloration does not occur when exposed to aqueous conditions for at least about 2 days.  
     
     
         25 . The composite of  claim 21 , wherein discoloration does not occur when exposed to aqueous conditions for at least about 5 days.  
     
     
         26 . The composite of  claim 21 , wherein discoloration does not occur when exposed to aqueous conditions for at least about 7 days.  
     
     
         27 . The composite of  claim 21 , wherein discoloration does not occur when exposed to aqueous conditions for at least about 14 days.  
     
     
         28 . The composite of  claim 21 , wherein the carrier comprises water.  
     
     
         29 . The composite of  claim 24 , wherein the carrier is a hydrogel.  
     
     
         30 . The composite of  claim 21 , wherein the particulate silver comprises nanoparticulate silver.  
     
     
         31 . The composite of  claim 21 , wherein the composite and an environment adjacent the composite do not discolor when the composite and the environment adjacent the composite is exposed to water for at least 24 hours.  
     
     
         32 . The composite of  claim 21 , wherein the composite and the environment adjacent the composite do not discolor when the composite and the environment adjacent the composite is exposed to water for at least 24 hours under oxidative conditions.  
     
     
         33 . An article that does not discolor when exposed to an aqueous envrionment for at least 24 hours, comprising the composite of  claim 21 .  
     
     
         34 . A personal care product having antimicrobial properties comprising the composite of  claim 21 .  
     
     
         35 . The personal care product of  claim 31 , wherein the personal care product is selected from a bandage, a cosmetic, a topical skin treatment, a wound dressing, a diaper, or a feminine care article.